在世界各地, 電子郵票的名稱分別曾經還有:
automatic stamp, variable value stamp, machine vending stamp, postage labels, electronical stamp...
最普遍是 ATM , 就是德文 "Automatenmarken" 的簡稱.
以下是萬國郵聯對電子郵票的定義:
According to the Postal Law of the UPU (passed at the UPU Congress at Hamburg, 1984) - postage stamps that are printed by electronical stamp vending machines. After inserting the necessary amount of money (coins, banknotes etc.) the customer usually gets a stamp directly printed on (security) paper by the machine. In all respects (denomination of value and country, symbol of the postal authorities etc.) this stamp corresponds to the traditional postage stamp.
